Cheap DIY tilt switches are great in a pinch

[fjordcarver] was looking for some mercury-free tilt switches that wouldn’t break the bank and that were easy to build. He also wanted something cheap, so instead of buying some tilt switches he devised his own that fit all of the criteria he set out. Now, these switches are not your typical fare, and they’re not small either. They are however, cheap, effective, and easy to manipulate/repair.

He picked up a package of metallic craft beads at the store and emptied out two bottles, saving one set of beads that happened to be conductive, i.e. not coated with paint or coloring. The beads were split between two jars, which were then sealed with corks that had a pair of straightened paperclips inserted through them. The bottles were oriented facing away from one another, then attached together with a piece of house wire. One of the leads from each jar was attached to this common wire, while the others were extended with hook up wire for use in the circuit he was building. Pictures definitely explain the mechanism far better than words can, so be sure to check out his tutorial to get a better look at them.

While they might look a bit rough, he says they work great, so give them a try if you have the need.

That’s more corrosion / dust sensitive than this solution, as contact surface is a lot larger with a lot of small balls.
I’ve seen the solution you propose, but it used gold plated contacts and a gold plated ball.

One could use steel shot used for duck hunting as the balls too. alot cheaper though probably need to get a larger quantity. You may be able to get some from a local gun shop though for cheap since you would just need a hand full.

I wonder how much current could run through these before the balls melt. I like vow V controls anyways, but where I use them they get beat up a lot & need to be fused with FA fuses. Neat idea!

I have a solution: copper BBs (most are copper plated steel). 1000 for probably less than the craft store beads (those places are so expensive!), but the containers and contacts would have to be larger

BB ammunition works great (if you have it), but you can also use copper filings. The sharp edges helped reduce oxide buildup. You can get scrap copper from copper wire or copper pipe. Aluminum filings might also work.

No need to go shopping for appropriately sized metallic beads, and then to test them and sort them by electrical conductivity.

I beg to differ a little bit. Sure, mercury pansies are the same people that force silly enviro and safety rules (I’m talking about evacuating an office floor if some Hg fluorescent tubes break, like in Germany(?))

When mercury contactors go bad, they explode.

Costs us $25k and three days of downtime every time one blew up at work, despite being in a sealed cabinet that nobody ever goes into …but you know, not enough money in the budget to replace them with non-Hg contactors (Under $150 each).

The recommended layman’s method for disposing of spilled but visible mercury blobs is to amalgamate it with tin, most easily any tin based solder. Just feed solder into the blob until all of it has hardened.

If spilled into cracks in floors or similar, it is recommended to contact some kind of poison information service or similar, since it could potentially leak mercury vapor over several years.

Who cares what happens to you, we are making new babies all the time. Making new Great Lakes that aren’t polluted with mercury is a lot harder. It takes very little mercury to poison a huge amount of water.

If you are concerned about the long term, you know that your switch with mercury comes from a batch of thousands, which account for alot of mercury. Maybe your switches won’t break, but you can’t tell what will happen to all of the switches that came out with them. So, some people just avoid all mercury because: 1) they can, 2) they care.

If you don’t care, you’ll never agree. You probably won’t even understand why someone would care. Hence, it’s stupid to care.

Depending on the decorative bead package price, it can be even cheaper if you buy plain metal balls. You can get 500 1/16″ carbon steel bearing balls for less than $5 before shipping from McMaster-Carr. You could experiment with different sizes (or even combinations) for the best flow/lowest angle of repose.

Having been hit by and still exposed to the dangers of IEDs I don’t appreciate the sarcasm about them. As for tilt switches being used for such an application, it is almost unheard of, at least in Afghanistan. Too much could go wrong with the emplacer and cause unintended detonation. The guys that build those things are rather smart, the guys using them are 99% likely to be illiterate, stone-aged, unwashed fanatics with enough training to dig a hole and hide the wires.

Great little tilt sensor, it does its job, and meets the creator’s requirements, exactly what it needs to be.

Since IED is not the general term it doesn’t necessarily mean iraq/afghanistan, people like the unibomber for instance also made ‘IED’, and in WWII soldiers often made IED for combat purposes.
Didn’t saving private ryan also have the guys make IED? And I once read an army soldiers basic manual and in it they also advise how to make homebrew things to stop tanks and such.

Hey cool my tilt sensor is on hack a day. Glad to see people like and hate it. It works. Good enough for me. How come the maker never knows this stuff. Cheers, I hope some of my other crap filters through here, really exciting to see it, although next time I should be told…wink wink, nudge nudge…..